Reservoir Levels Drop to 46%
The Ebro river basin in Catalonia is now officially in a state of prolonged drought, with reservoirs at 46% of capacity after a hot, dry summer. The Confederación Hidrográfica del Ebre (CHE), the regional water authority, confirmed the declaration for the Segre and Noguera Pallaresa river basins, as well as the Éssera-Noguera Ribagorêna basin, during its 2025–2026 hydrological year review. At the end of the hydrological year, total stored water in the basin stood at 3,591 hectometres cubed, below both last year's 4,282 hectometres cubed (54.9%) and the five-year average of 3,757 hectometres cubed (48.2%).
Sharp Decline After Wet Winter
The decline follows an exceptionally wet winter, when snowpack in the Pyrenees reached a historic high of 2,000 hectometres cubed in February, equivalent to about 30% of the water stored in CHE reservoirs. Heavy winter rains had boosted reservoir levels to 6,905 hectometres cubed (88.5%) by early June, well above the five-year average for that time. However, an early spring thaw accelerated snowmelt, and a prolonged, hot summer increased demand for irrigation. Some irrigation communities used up to 20% more water than usual, leading to the sharp drop in reserves.
Coastal Flooding Contrasts With Inland Drought
The situation contrasts sharply with coastal areas of Catalonia, which have recently experienced heavy rainfall and flooding. This divergence highlights regional climate extremes within the same territory. Mario Carreras, CHE's hydrology chief, stressed that while the irrigation season concluded without major restrictions thanks to strong winter reserves, caution is needed for the next season starting in March 2027.
We must act with caution in the coming months, as the accumulated water reserve from winter has been significantly depleted.
Data Shows Steady Decline
According to the CHE's weekly reservoir report dated 20 April 2026, total stored water was 6,548 hectometres cubed (84% capacity). By the end of the hydrological year, levels had dropped by over 2,900 hectometres cubed since the June peak. The February 2026 report showed 6,366 hectometres cubed stored (81.6%), indicating a steady decline throughout the spring and summer months (see full data and historical comparison).
Concern Over Data Centres' Water Use
The CHE is also monitoring water demand from proposed data centres, particularly those supporting artificial intelligence systems. Thirteen administrative procedures are currently open, with an estimated total annual water consumption of 5 hectometres cubed. While this is small compared to the basin's total industrial use of around 700 hectometres cubed per year, Miguel García, head of the CHE's Hydrological Planning Office, said specific tracking is needed due to projected growth in AI infrastructure.
Although current consumption is limited, the expected expansion of AI systems means we must closely monitor their future water needs.
Reported by chebro.es, La Valira.
